Film element and method for production of spatially distinct dye and silver photographic images

ABSTRACT

A silver halide photographic color film element which includes a separate layer containing silver in an amount at least equivalent to the total silver in remaining dye forming silver halide layers of said element. The element may be used in a method wherein differential exposure thereof to desired dye and silver images, followed by differential development, bleaching and fixing, provides the element with spatially distinct dye and silver images.

United States Patent 191 v Newman et al.

[ June 25, 1974 FILM ELEMENT AND METHOD FOR PRODUCTION OF SPATIALLY DISTINCT DYE AND SILVER PHOTOGRAPHIC IMAGES [75] Inventors: Norman Newman; Richard S. Fisch,

both of Saint Paul, Minn.

[73] Assignee: Minnesota Mining and Manufacturing Company, St. Paul, Minn.

22 Filed: June 13, 1972 211 App]. No.: 262,179

[52] u.s.c| ..96/4,96/59,96/74 [51] Int.Cl G03c 7/24, 603C 5/50 58 Field oiSearch 96/4, 39, 74, 59

[56] 7 References Cited- UNITED STATES PATENTS 2,235,033 3/l94l Miler 96/4 2,275,710 3/1942 Wilder ..96/4 2,348,735 5/1944 Gaspar ..96/74 Primary ExaminerRonald H. Smith Assistant Examiner-Alfonso T. Suro Pico Attorney, Agent, or Firm-Alexander, Sell, Steldt &

Delahunt [5 7] ABSTRACT 18 Claims, No Drawings FILM ELEMENT AND METHOD FOlR PRODUCTION OF SPATIALLY DISTINCT DYE AND SILVER PHOTOGHIC IMAGES This invention relates to photographic color materials, and particularly relates to photographic color print films useful for making copies of motion picture films and having separate, silver sound track images.

In producing copies of motion picture films bearing sound tracks, it is customary to begin with a master negative film and a separately recorded sound track, and thereafter to print the picture areas of the negative film, and the sound track, upon positive print stock. The resulting film copy is a positive and bears a sound track.

Of the several sound track systems which have been suggested, an optical sound track employing a deposit of metallic silver has enjoyed wide popularity. Silver sound track images are preferred because of the excellent fidelity they provide. Although dye images have been suggested for sound track systems, these have generally been unsatisfactory because of their lack of density in the infrared portion of the spectrum to which phototubes of the type employed in sound track reproductions are primarily sensitive.

In a presently popular method for making copies of sound motion picture films, latent images of the picture (from the master negative film) and the sound track are provided on a color positive copying film, the sound track image being provided along the edge of the film. The film is then developed in a color photographic developer and bleached in a photographic bleach bath, the latter serving to oxidize developed silver in the print film. Thereafter, a silver halide developer is applied to the edge of the bleached film corresponding to the sound track to provide a silver sound track image, and the print film is thereafter fixed to remove all silver halide from both the picture and sound track of the film. The resulting film, accordingly, bears silver-free picture areas and also bears, along one edge thereof, a silver sound track image.

It will be understood that the above method requires re-development of the silver sound track between the bleaching and fixing steps. Re-development of the sound track area is normally accomplished by applying a thin strip or band of developer solution (ordinarily a thickened black-and-white developer such as hydroquinone, etc.) along the edge of the film which had been exposed to the sound track image. It will further be understood that this re-development procedure is subject to a number of problems, among which are problems associated with possible migration of the band of blackand-white developer into picture areas of the film, problems associated with the apparatus which is employed to accurately and continuously supply a thin band of black-and-white developer over a given width of the copy film, and problems associated with the formulation and standardization of the normally viscous, fast'acting black-and-white developer material. Of particular importance, as noted above, is thefact that the so-described process contains numerous sequential steps which lengthen processing time and provide opportunities for processing failures. For example, the redevelopment step discussed above, which is absolutely 6 essential to the success of this process, necessitates'the use of separate bleach and fix treatments, and hence prohibits the use of single bleach-fix solutions which have become popular in other photographic processes.

It is an object of the present invention to provide a silver halide photographic color film element capable of being processed in a bleach-fix solution to provide spatially distinct color (e. g., dye) and silver images.

It is another object of the invention to provide a silver halide photographic color film element capable of providing spatially distinct color and silver images by an abridged, simplified processing method.

It is yet another object of the invention to provide a method for developing a silver halide photographic color film element in which spatially distinct color and silver images are simultaneously produced.

It is a further object of the invention to provide a processing method for silver halide photographic color film wherein a bleach-fix bath is employed to provide spatially distinct color and silver images.

In one embodiment, the present invention relates to a silver halide photographic color film element which comprises at least one dye-forming silver halide photographic emulsion layer sensitized to a portion of the visible spectrum. The element is characterized by including an additional, separate silver halide emulsion layer which contains silver in an amount at least equivalent, in weight per unit area, to the total amount of silver in the at least one dye-forming silver halide layer. The additional, separate silver halide layer preferably contains from about 30 to about milligrams of silver per square decimeter, and most preferably is a non-dyeforming layer; that is, the layer is preferably devoid of color couplers capable of reacting with oxidized color developer to form dyes. The element preferably includes at least three dye-forming layers, each sensitized to a different portion of the visible spectrum.

In another embodiment, the invention relates to a method for the production of a unitary photographic recording bearing spatially separate dye and silver images. The method comprises:

a. providing a unitary silver halide photographic element which includes at least one dye-forming, light-sensitive layer sensitized to a portion of the visible spectrum, and including an additional, separate silver halide layer containing silver in an amount at least equivalent, in weight per unit area, to the total silver in the at least one dye-forming layer;

b. providing the element with spatially distinct latent images corresponding respectively to color and silver images such that the additional, separate layer is fully developable only in areas corresponding to the silver image under development conditions just sufficient to cause full development of the dye image in the at least one dye-forming layer;

c. developing the exposed element in a photographic color developing solution to cause development of the spatially-distinct silver and dye images; and

d. bleaching and fixing the element under conditions permitting full oxidation and removal of silver in the dye-image areas of the element but insufficient to oxidize and remove all of the silver in the silverimage areas.

The photographic film element of the present invention, as noted above, preferably includes at least 3 dyeforming silver halide photographic emulsion layers, each sensitized to a different portion of the visible spectrum. Film elements containing at least 3 dye-forming silver halide photographic emulsion layers, as described, are widely known to the art, and commonly are referred to as tripack materials. For example, the element may include 3 layers sensitized respectively to blue, green and red light. Normally, each of the dyeforming silver halide layers has incorporated therein a photographic color coupler of the type known to the art. After exposure of such a dye-forming layer to a colored image, the layer is developed in a photographic color developer (commonly a primary aromatic amine developer such as, for example p-(N-ethyl-N-B-hydroxyethyl)-aminoaniline). The developer reduces silver halide to metallic silver in light-struck areas of the layer, and in turn is oxidized. The oxidized developer then reacts with the color coupler contained in the layer to form a dye, thus providing a dye-colored image. As referred to above, the silver in such areas may later be removed by bleaching and fixing processes. The principles of color photography are widely known to the art, and accordingly need not be described in great detail herein.

The color film elements of the invention include yet another silver halide layer in addition to those required to form a colored image; this layer, referred to herein as an additional, separate silver halide layer, contains silver halide in an amount at least equivalent, in weight of silver per unit area, to the total silver in the at least 3 dye-forming layers. The additional, separate layer preferably is a non-dye-forming layer, and preferably contains from about 30 to about 90 milligrams of silver per square decimeter. The additional, separate silver halide layer may be positioned in the color film element between the other silver halide layers, as an outer layer of the element, or (preferably) between the substrate and the first silver halide layer. As is known in the art, silver halide photographic elements may be prepared by coating upon a suitable substrate (e.g., polyester or cellulose triacetate film) a plurality of silver halide layers and often one or more filter layers.

Silver halide emulsions themselves, of course, are well known to the photographic art. These emulsions may make use of silver chloride, silver bromide, or silver iodide, or mixtures thereof, and selection from among the numerous emulsions employed in photographic color film materials is not critical to the invention. The various emulsions employed in silver halide layers of color films of the invention may, of course, contain various adjuvants known to the photographic art such as hardeners, sensitizing dyes, wetting agents, coating aids, antifog additives, etc.

In the present invention, as noted above, photographic film is first provided with spatially distinct latent images corresponding respectively to color and silver images, the color image being that, for example, of

a scene and the silver image being, for example, that of a sound track, thereafter the film is developed, bleached and fixed to provide only color images in one area of the film and only silver (e.g., sound track) images in another portion of the film, the color and silver images being spatially distinct. To accomplish this result, it is necessary that the bleach step be capable of bleaching (i.e., oxidizing) all of the silver in the color image areas but incapable of oxidizing all of the silver in the silver image areas.

Whereas the at least 3 dye-forming layers of the silver halide element are sensitized to different portions of the visible spectrum, it is desired that the additional,

separate silver halide layer be less sensitive to these portions of the spectrum, and preferably sensitized to a different portion (e.g., the infra-red portion) of the spectrum. For example, in a preferred embodiment the additional separate layer has a sensitivity such that upon exposure of the photographic element to light to which the dye forming layers are sensitized, the light being provided in an amount just sufficient to permit the dye-forming layers to be normally color developed to their full density, followed by development of the element to an extent just sufficient to completely develop the dye-forming layers, and further followed by bleach ing the element under conditions just sufficient to oxidize all of the developed silver in the dye-forming areas, then any developed silver in the additional, separate layer is also oxidized. In this respect, the amount of light just sufficient to permit the dye-forming layers to be normally color developed to their full density can be determined easily by trial and error using a tungsten light source and appropriate color filters. By normally color developed is meant that the film is exposed to a color development solution of the type known to the art; e.g., aqueous alkaline solutions which include a primary aromatic amine color developing agent. The extent of development of the element in a black and white photographic developer (e.g., a developer containing hydroquinone) can be determined readily by measuring the amount of silver which is formed in each of the layers of the photographic element by electron microprobe analysis techniques, as described in Birks, Electron Probe Micro Analysis, John Wiley and Sons, New York, 1963. The amount of exposure to light, as just mentioned, can be determined by common photographic techniques employing, for example, D-log E curves for each of the dye-forming silver halide layers. The intensity of black and white development can be determined, as noted, by electron probe microanalysis wherein one chooses that development condition which completely develops the dye-forming layers such that an increase in development intensity yields no further increase in developed silver in the dye-forming layers. Thereafter, the element is bleached under conditions just sufficient to oxidize all developed silver in the dye-forming layers, and the bleaching intensity required for this step can also be determined by trial and error, measuring the amount of residual silver in each of the dye-forming layers, and in the additional separate layer after bleaching the element under given conditions, and fixing the element.

Preferably, the sensitivity of the additional, separate layer in photographic elements of the invention is such that upon exposure of the layer to light to which the dye-forming layers are sensitized in an amount just sufficient to permit the dye-forming layers to be developed, with normal color development, to their full density, then substantially no image silver is developed in the additional separate layer. Again, standard photographic techniques may be employed to measure the intensity of light which is required, and electron probe analysis may be employed to measure the amount of silver in the various layers of the element.

Under certain circumstances it may be desirable to include a masking layer in the film element. Masking layers are generally described in Glaflddes, Photographic Chemistry Vol. II, 1960, Fountain Press Publications, Ch. XXIX, pp. 573-592.

In this invention, the additional, separate silver halide layer may serve as both the masking layer and the sound image layer. This can be achieved by the inclusion of an appropriate masking coupler in the additional, separate layer, providing only that the additional, separate layer has a spectral sensitivity distinct from those of the dye forming other layers, such as a sensitivity outside or substantially outside the visible spectrum, or just outside the range of sensitivity of the image dye forming layers. The silver halide may, for example, be sensitized to the infra-red portion of the electromagnetic spectrum.

In the method of the present invention, a photographic unitary silver halide element as described above is provided with spatially distinct latent images corresponding respectively to color and silver images such that the additional separate layer of the element is fully developable only in areas corresponding to the silver image under development conditions just sufficient to cause full development of the dye images in the at least 3 dye-forming layers. For example, referring to motion picture color print film, the film is first provided with a latent image corresponding to the color negative image on the original motion picture film (known as the negative master film). Thereafter, the sound track which is desired is recorded onto the print film along one edge thereof using, for example, an infra-red recording light source. Thereafter the print film is normally color developed to give rise to both silver and dye images in those areas of the print film corresponding to the color negative master film image, and to provide a silver sound track image along the edge of the film in the additional, separate silver halide layer. The silver image in the sound track area, of course, must .be heavier than the silver image in the color image areas of the film so that, upon subsequent bleaching and fixing sufficient to remove the silver from the colored image areas, sufficient silver remains in the sound track to provide adequate sound reproduction. It must be understood that the entire photographic element, including both color and silver image areas, is treated uniformly with the bleaching and fixing solutions.

It has been found desirable to employ, in the method of the present invention, a bleach-fix bath which includes both bleaching and fixing components. Such baths are well known to the photographic art.One such solution which has given excellent results employs, as the oxidizing agent thereof (the bleaching agent), a water-soluble salt of ethylenediamine tetraacetatoferrate (Ill) such as the sodium salt thereof. Further, in a preferred embodiment of the bleach-fix solution employs as the silver halide solvent (the fixing agent) a source of thiosulfate ions such as ammonium thiosulfate.

The invention may be more easily understood by reference to the following illustrative non-limiting examples:

EXAMPLE 1 ble of forming a cyan dye with the oxidation product of a paraphenylene diamine developer, and dye-sensitized to the red region of the spectrum, was thereafter coated over the first silver halide layer to a coating weight of 5 milligrams per square decimeter. The resulting photographic element was thereafter exposed, in a sensitometer, as follows: One area of the element was exposed to minus red light (8400 meter candle seconds exclusive of filtration, the filtration consisting of Wratten 47B,58 and 2B filters). Another, previously unexposed area of the element was exposed to red light (420 meter candle seconds exclusive of filtration, the filtration consisting of Wratten 29 and 2B filters). The first exposure provided a latent image corresponding to the desired silver (e.g., sound track) image in the greensensitive emulsion, and the second exposure provided a latent image in the red-sensitive cyan dye-forming layer.

The exposed element was then processed as follows:

Water wash 30 seconds Developer 8 minutes Bleach-fix 30 seconds Wash 5 minutes Stabilizer bath 15 seconds A color developer containing a paraphenylenediamine derivative as described in Production of Motion Pictures in Color Using Eastman Color Films".

An aqueous solution containing 0.8 moles per liter of ammonium thiosulfate and 0.02 moles per liter of the sodium salt of ethylencdiaminetetraacctatoferrale (Ill), plus 33% excess ethylenediaminctc\raacetic acid.

After processing, silver and dye images were visible in those areas of the element exposed to the first exposure, as set forth above. Only a cyan dye image was visible in the areas exposed during the second exposure.

EXAMPLE 2 A photosensitive element identical to that of Example l was prepared except that the cyan dye-forming emulsion layer was placed between the green-sensitized silver halide layer and the support. The resulting photographic element was exposed in a manner identical to that of Example 1 and was then processed in the following sequence:

Water wash 30 seconds Developer" 8 minutes Bleach-fix" 4 minutes Wash 5 minutes Stabilizer bath 15 seconds "Identical to that of Example 1.

After processing, silver and dye images were visible in the area exposed during the first exposure, but only a cyan dye image was visible in the area of the second exposure. X-ray fluorescence measurements of the processed element showed that the amount of silver in the maximum density areas of the silver image was about 24 milligrams per square decimeter, whereas no silver could be detected in those areas of the element containing only the cyan dye image.

EXAMPLE 3 A photographic color positive print film was prepared by coating onto a cellulose acetate base, the following sequential layers:

l. A stabilized and hardened silver bromoiodide emulsion (2 mole percent iodide) having a gelatin coating weight of 2 grams per square meter and a silver coating weight of 5.5 milligrams per square decimeter,

the emulsion further Containing 1 gram per square meter of a yellow coupler of the formula COCHzCONH which was introduced into the emulsion by the solvent dispersion technique. The coupler dispersion was prepared by dissolving 6 grams of the coupler in milliliters of dibutylphthalate and milliliters of ethyl acetate, and dispersing the resulting solution in 60 milliliters of a 5 percent water solution of gelatin containing 0.5 grams of Tergitol 4 as a surfactant.

. 2. A hardened gelatin layer, at 0.5 grams per square meter.

3. A red-sensitized, stabilized and hardened silver chloro bromide emulsion mole percent bromide) having a silver coating weight of 6 milligrams per square decimeter and a gelatin coating weight of 2.4 grams per square meter. This emulsion also contained 0.7 grams per square meter of a cyan coupler of the formula the coupler having been introduced into the emulsion by the solvent dispersion technique as described above.

4. An intermediate hardened gelatin layer, 0.5 grams per meter squared.

5. A green-sensitized, stabilized and hardened silver chloro bromide photographic emulsion layer (25 mole percent bromide) having a silver coating weight of 8.5 milligrams per square decimeter and a gelatin coating weight of 3.2 grams per square meter. This emulsion also contains 0.7 grams per square meter of a coupler of the formula 01- OCHa which was introduced into the emulsion by the solvent dispersion technique as described above.

6. An intermediate layer of hardened gelatin, 0.5 grams per square meter.

7. A blue-sensitive silver chloro bromide photographic emulsion, stabilized and hardened and having a silver coating weight of 60 grams per square decimeter and a gelatin coating weight of 9.0 grams per square meter, this emulsion containing no color coupler, but being dye sensitized to the infra-red region of the spectrum.

8. A protective coating of hardened gelatin having a gelatin coating weight of 0.6 grams per square meter.

The resulting element may be employed as a motion picture print film by exposure thereof first through a color-negative master motion picture film, and exposure of one edge of the film to sound-modulated infrared light. The film may then be developed, bleached and fixed by methods customary in the photographic art, the bleaching step being carried out only for sufficient time to oxidize all of the silver in the non-sound track areas of the film. The resulting print film will be found to contain an efficient, silver sound track along one edge thereof and a silver-free, 3-component dye image in the remainder of the film.

What we claim is:

1. A silver halide photographic color film element which comprises a substrate and on one side of said substrate at least one dye-forming silver halide photographic emulsion layer sensitized to a portion of the visible spectrum, said element being characterized by including an additional, separate non-dye-forming silver halide emulsion layer which contains silver in an amount at least equivalent to the total amount of silver, in weight per unit area, of all dye-forming silver halide layers in the element sensitized to a portion of the visible spectrum.

2. A silver halide photographic color film element which comprises a substrate and on one side of said substrate at least one dye-forming silver halide photographic emulsion layer sensitized to a portion of the visible spectrum, said element being characterized by including an additional, separate silver halide emulsion layer with a spectral sensitivity outside the visible spectrum which contains silver in an amount at least equivalent to the total amount of silver, in weight per unit area, of all dye-forming silver halide layers in the element sensitized to a portion of the visible spectrum.

3. The color film element according to claim 1 wherein said additional, separate layer contains from about 30 to about mg. of silver per square decimeter.

4. The photographic color film element of claim 1 wherein the'additional, separate layer contains a dye coupler and has a spectral sensitivity distinct from that of all dye-forming layers and outside the range of sensitivity of all dye-forming layers sensitized to a portion of the visible spectrum.

5. The photographic color film element of claim 1 in which the additional, separate layer contains silver in an amount at least equivalent to the total amount of silver, in weight per unit area, present in the dye-forming silver halide layers.

6. The photographic color film element of claim 1 wherein said element contains at least three dyeforming silver halide photographic emulsion layers, each sensitized to a different portion of the visible spectrum.

7. The photographic color film element according to claim 1 wherein said additional, separate layer has a sensitivity such that upon exposure of said element to light to which said at least one dye-forming layer is sensitized to an amount just sufficient to permit said dyefonning layer to be normally color-developed to its full density, followed by development of said element in a black and white photographic developer under conditions just sufficient to completely develop said at least one dye-forming layer and bleaching under conditions just sufficient to oxidize all developed silver in said at least one dye-forming layer, any developed silver in said additional, separate layer is also oxidized.

8. The photographic color film element according to claim 7 wherein the sensitivity of said additional, sepa rate layer is such that upon exposure of said layer to light to which said at least one dye-forming layer is sensitized, in an amount just sufficient to permit said at least one dye-forming layer to be developed to its full density, substantially no image silver is developable in said additional, separate layer.

9. The element of claim 1 wherein said additional, separate layer is sensitized to a region of the spectrum different from that of the at least one dye-forming layer.

10. The element of claim 9 wherein said additional, separate layer is sensitized to the infra-red portion of the spectrum.

11. A method for the production of a unitary photographic recording bearing spatially distinct dye and silver images, said method comprising a. providing a unitary silver halide photographic element which includes a substrate and on one side of said substrate at least one dye-forming, light sensitive silver halide layer sensitized to a portion of the visible spectrum, and including an additional separate silver halide emulsion layer with a spectral sensitivity outside the visible spectrum containing silver in an amount at least equivalent, in weight per unit area, to the total silver in all dye-forming layers in the element;

b. providing said element with spatially distinct latent images by exposure to the respective range of sensitivities of the dye-forming and additional layer corresponding respectively to color and silver images such that said additional, separate layer is fully developable only in areas corresponding to said silver image under development conditions just sufficient to cause full development of said dye image in said at least one dye-forming layer;

c. developing said exposed element in a photographic color developing solution so as to provide said respective silver and dye images in said element, and

d. bleaching and fixing said element under conditions permitting full oxidation and removal of silver in dye-image areas but insufficient to oxidize and remove all silver in said silver-image areas.

12. A method for the production of a unitary photographic recording bearing spatially distinct dye and silver images, said method comprising a. providing a unitary silver halide photographic element which includes a substrate and on one side of said substrate at least one dye-forming, light sensitive silver halide layer sensitized to a portion of the visible spectrum, and including an additional, separate non-dye-forming silver halide layer containing silver in an amount at least equivalent, in weight per unit area, to the total silver in the element in dye-forming layers;

b. providing said element with spatially distinct latent images by exposure to the respective range of sensitivities of the dye-forming and additional layer corresponding respectively to color and silver images such that said additional, separate layer is fully developable only in areas corresponding to said silver image under development conditions just sufficient to cause full development of said dye image in said at least one dye-forming layer;

c. developing said exposed element in a photographic color developing solution so as to provide said respective silver and dye images in said element, and

d. bleaching and fixing said element under conditions permitting full oxidation and removal of silver in dye-image areas but insufficient to oxidize and remove all silver in said silver-images areas.

13. The method of claim 12 wherein said bleaching and said fixing are accomplished by treating said element in a bleach-fix bath.

14. The method according to claim 13 wherein said bleach-fix bath includes, as an oxidizing agent thereof, a water-soluble salt of ethylenediaminetetraacetatoferrate (III).

15. The method according to claim 13 wherein said bleach-fix bath contains, as a silver halide solvent, at source of thiosulfate ion.

16. The method according to claim 12 wherein said additional, separate layer contains silver halide in a I concentration equivalent to -90 milligrams of silver per square decimeter.

17. Method for the production of a photographic color reproduction of a length of color motion picture film bearing a sound track along one edge thereof, said method comprising:

a. providing a unitary silver halide photographic element which includes at least a substrate and on one side of said substrate 3 dye-forming, light-sensitive silver halide layers, each layer sensitized to a different region of the visible spectrum, and an additional, separate layer which contains silver in an amount at least equivalent, in weight per unit area, to the total silver in said at least 3 dye-forming layers;

b. differentially exposing said element to separate light images corresponding to the respective range of sensitivity for the dye-forming and additional layer, corresponding respectively to said dye and sound track images of said motion picture film under conditions rendering said additional, separate layer fully developable only in areas thereof corresponding to said sound track image;

c. developing said exposed element in a color developing solution;

d. bleaching said element under conditions permitting full oxidation of silver in said dye-image areas but insufficient to oxidize all of said silver in said sound track area; and

e. fixing said element.

18. The method of claim 17 wherein said bleaching and fixing steps are accomplished by treatment of said element in a bleach-fix bath. 

2. A silver halide photographic color film element which comprises a substrate and on one side of said substrate at least one dye-forming silver halide photographic emulsion layer sensitized to a portion of the visible spectrum, said element being characterized by including an additional, separate silver halide emulsion layer with a spectral sensitivity outside the visible spectrum which contains silver in an amount at least equivalent to the total amount of silver, in weight per unit area, of all dye-forming silver halide layers in the element sensitized to a portion of the visible spectrum.
 3. The color film element according to claim 1 wherein said additional, separate layer contains from about 30 to about 90 mg. of silver per square decimeter.
 4. The photographic color film element of claim 1 wherein the additional, separate layer contains a dye coupler and has a spectral sensitivity distinct from that of all dye-forming layers and outside the range of sensitivity of all dye-forming layers sensitized to a portion of the visible spectrum.
 5. The photographic color film element of claim 1 in which the additional, separate layer contains silver in an amount at least equivalent to the total amount of silver, in weight per unit area, present in the dye-forming silver halide layers.
 6. The photographic color film element of claim 1 wherein said element contains at least three dye-forming silver halide photographic emulsion layers, each sensitized to a different portion of the visible spectrum.
 7. The photographic color film element according to claim 1 wherein said additional, separate layer has a sensitivity such that upon exposure of said element to light to which said at least one dye-forming layer is sensitized to an amount just sufficient to permit said dye-forming layer to be normally color-developed to its full density, followed by development of said element in a black and white photographic developer under conditions just sufficient to completely develop said at least one dye-forming layer and bleaching under conditions just sufficient to oxidize all developed silver in said at least one dye-forming layer, any developed silver in said additional, separate layer is also oxidized.
 8. The photographic color film element according to claim 7 wherein the sensitivity of said additional, separate layer is such that upon exposure of said layer to light to which said at least one dye-forming layer is sensitized, in an amount just sufficient to permit said at least one dye-forming layer to be developed to its full density, substantially no image silver is developable in said additional, separate layer.
 9. The element of claim 1 wherein said additional, separate layer is sensitized to a region of the spectrum different from that of the at least one dye-forming layer.
 10. The element of claim 9 wherein saiD additional, separate layer is sensitized to the infra-red portion of the spectrum.
 11. A method for the production of a unitary photographic recording bearing spatially distinct dye and silver images, said method comprising a. providing a unitary silver halide photographic element which includes a substrate and on one side of said substrate at least one dye-forming, light sensitive silver halide layer sensitized to a portion of the visible spectrum, and including an additional separate silver halide emulsion layer with a spectral sensitivity outside the visible spectrum containing silver in an amount at least equivalent, in weight per unit area, to the total silver in all dye-forming layers in the element; b. providing said element with spatially distinct latent images by exposure to the respective range of sensitivities of the dye-forming and additional layer corresponding respectively to color and silver images such that said additional, separate layer is fully developable only in areas corresponding to said silver image under development conditions just sufficient to cause full development of said dye image in said at least one dye-forming layer; c. developing said exposed element in a photographic color developing solution so as to provide said respective silver and dye images in said element, and d. bleaching and fixing said element under conditions permitting full oxidation and removal of silver in dye-image areas but insufficient to oxidize and remove all silver in said silver-image areas.
 12. A method for the production of a unitary photographic recording bearing spatially distinct dye and silver images, said method comprising a. providing a unitary silver halide photographic element which includes a substrate and on one side of said substrate at least one dye-forming, light sensitive silver halide layer sensitized to a portion of the visible spectrum, and including an additional, separate non-dye-forming silver halide layer containing silver in an amount at least equivalent, in weight per unit area, to the total silver in the element in dye-forming layers; b. providing said element with spatially distinct latent images by exposure to the respective range of sensitivities of the dye-forming and additional layer corresponding respectively to color and silver images such that said additional, separate layer is fully developable only in areas corresponding to said silver image under development conditions just sufficient to cause full development of said dye image in said at least one dye-forming layer; c. developing said exposed element in a photographic color developing solution so as to provide said respective silver and dye images in said element, and d. bleaching and fixing said element under conditions permitting full oxidation and removal of silver in dye-image areas but insufficient to oxidize and remove all silver in said silver-images areas.
 13. The method of claim 12 wherein said bleaching and said fixing are accomplished by treating said element in a bleach-fix bath.
 14. The method according to claim 13 wherein said bleach-fix bath includes, as an oxidizing agent thereof, a water-soluble salt of ethylenediaminetetraacetatoferrate (III).
 15. The method according to claim 13 wherein said bleach-fix bath contains, as a silver halide solvent, a source of thiosulfate ion.
 16. The method according to claim 12 wherein said additional, separate layer contains silver halide in a concentration equivalent to 30-90 milligrams of silver per square decimeter.
 17. Method for the production of a photographic color reproduction of a length of color motion picture film bearing a sound track along one edge thereof, said method comprising: a. providing a unitary silver halide photographic element which includes at least a substrate and on one side of said substrate 3 dye-forming, light-sensitive silver halide layers, each layer sensitized to a different region of the visible spectruM, and an additional, separate layer which contains silver in an amount at least equivalent, in weight per unit area, to the total silver in said at least 3 dye-forming layers; b. differentially exposing said element to separate light images corresponding to the respective range of sensitivity for the dye-forming and additional layer, corresponding respectively to said dye and sound track images of said motion picture film under conditions rendering said additional, separate layer fully developable only in areas thereof corresponding to said sound track image; c. developing said exposed element in a color developing solution; d. bleaching said element under conditions permitting full oxidation of silver in said dye-image areas but insufficient to oxidize all of said silver in said sound track area; and e. fixing said element.
 18. The method of claim 17 wherein said bleaching and fixing steps are accomplished by treatment of said element in a bleach-fix bath. 